Organic light emitting display substrate and method for manufacturing the same

ABSTRACT

The present disclosure provides an organic light emitting display substrate and a method for manufacturing the same. The organic light emitting display substrate includes a substrate, and a drive transistor and an organic light emitting diode disposed on the substrate. In a direction away from the substrate, the organic light emitting diode successively includes: a first reflective electrode, an organic light emitting layer, and a second reflective electrode. A drain of the drive transistor is electrically coupled to the first reflective electrode. The organic light emitting display substrate further includes a light guide layer. One side surface of the light guide layer is the light incident surface. The light incident surface is disposed opposite to the light outgoing surface of the organic light emitting diode so that the light emitted from the light outgoing surface enters the light guide layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority from the Chinese patentapplication No. 201810943179.2 filed on Aug. 17, 2018, the disclosure ofwhich is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the technical field of displaytechnology, and particularly relates to an organic light emittingdisplay substrate and a method for manufacturing the same.

BACKGROUND

An organic light emitting display device formed by active-matrix organiclight emitting diodes (AMOLEDs) has excellent characteristics in powerconsumption and image, and thus is applied more and more widely.

SUMMARY

The present disclosure provides an organic light emitting displaysubstrate including a substrate, and a drive transistor and an organiclight emitting diode disposed on the substrate,

where in a direction away from the substrate, the organic light emittingdiode successively includes: a first reflective electrode, an organiclight emitting layer, and a second reflective electrode, where theorganic light emitting layer includes a light outgoing surface throughwhich light is emitted outside from the organic light emitting layer anda non-light outgoing surface through which no light is emitted outsidefrom the organic light emitting layer, and a drain of the drivetransistor is electrically coupled to the first reflective electrode;

the organic light emitting display substrate further includes: a lightguide layer including a light incident surface through which light isincident into the light guide layer, where the light incident surface isdisposed opposite to the light outgoing surface of the organic lightemitting diode so that the light emitted from the light outgoing surfaceenters the light guide layer which is configured to cause the lightentering from the light incident surface to be emitted from a surface ofthe light guide layer proximal to the substrate; and

the drive transistor is disposed at a side of the light guide layerdistal to the substrate.

In an embodiment, one side surface of the organic light emitting layeris the light outgoing surface, while the rest side surface is thenon-light outgoing surface; and one side surface of the light guidelayer is the light incident surface.

In an embodiment, the organic light emitting display substrate furtherincludes a first insulating layer disposed between the light outgoingsurface and the light incident surface, and the light incident surfaceand the light outgoing surface are disposed opposite to each other bythe first insulating layer.

In an embodiment, the first insulating layer is made of a transparentmaterial.

In an embodiment, the transparent material includes an inorganicinsulating material selected from the group consisting of SiOx, SiNx,and AlOx.

In an embodiment, the organic light emitting display substrate furtherincludes: a first light-reflecting layer disposed between the lightguide layer and the drive transistor, and covering a surface of thelight guide layer distal to the substrate.

In an embodiment, the organic light emitting display substrate furtherincludes: a transparent conductive layer disposed between the firstlight-reflecting layer and the light guide layer, where at least a partof the transparent conductive layer is superposed with the firstlight-reflecting layer, and the transparent conductive layer extendsbetween the light outgoing surface and the light incident surface to becoupled to the first reflective electrode of the organic light emittingdiode; and a drain of the drive transistor is coupled to the firstlight-reflecting layer made of a conductive material.

In an embodiment, the transparent conductive layer extends between theorganic light emitting layer and the first reflective electrode.

In an embodiment, the organic light emitting display substrate furtherincludes: an electrode layer disposed in a same layer as a gate of thedrive transistor, and coupled to the gate; where the electrode layer isdisposed opposite to at least a part of the first light-reflecting layerto form a first capacitor.

In an embodiment, the organic light emitting display substrate furtherincludes: a metal layer disposed in a same layer as the drain of thedrive transistor at a side of the electrode layer distal to thesubstrate, and coupled to the drain; where at least a part of the metallayer is disposed opposite the electrode layer to form a secondcapacitor.

In an embodiment, the organic light emitting display substrate furtherincludes: a second light-reflecting layer disposed outside the non-lightoutgoing surface of the organic light emitting layer, and configured toreflect light emitted from the non-light outgoing surface back to theorganic light emitting layer.

In an embodiment, the light guide layer includes: a reflective structuredisposed on each surface of the light guide layer except the lightincident surface and the surface proximal to the substrate, andconfigured to reflect light emitted from inside of the light guide layertoward the surface back into the light guide layer.

In an embodiment, at least a part of the second reflective electrode isdisposed at a side of the drive transistor distal to the substrate andcovers the drive transistor.

In an embodiment, the organic light emitting display substrate furtherincludes: a planarization layer disposed at the side of the light guidelayer distal to the substrate, and in contact with the light guidelayer, the planarization layer having a refractive index smaller thanthat of the light guide layer.

In an embodiment, the organic light emitting display substrate furtherincludes: a color filter layer disposed at a side of the light guidelayer proximal to the substrate; and a transparent insulating layerdisposed between the color filter layer and the light guide layer, thetransparent insulating layer having a refractive index greater than thatof the light guide layer.

The present disclosure further provides a method for manufacturing anorganic light emitting display substrate, including:

disposing a drive transistor and an organic light emitting diode on asubstrate so that in a direction away from the substrate, the organiclight emitting diode successively includes: a first reflectiveelectrode, an organic light emitting layer, and a second reflectiveelectrode, where the organic light emitting layer includes a lightoutgoing surface through which light is emitted outside from the organiclight emitting layer and a non-light outgoing surface through which nolight is emitted outside from the organic light emitting layer, and adrain of the drive transistor is electrically coupled to the firstreflective electrode;

where the disposing the drive transistor and the organic light emittingdiode on the substrate further includes disposing a light guide layer onthe substrate so that the light guide layer includes a light incidentsurface through which light is incident into the light guide layer, thelight incident surface is disposed opposite the light outgoing surfaceof the organic light emitting diode, the light emitted from the lightoutgoing surface enters the light guide layer which is configured tocause the light entering from the light incident surface to be emittedfrom a surface of the light guide layer proximal to the substrate, andthe drive transistor is disposed at a side of the light guide layerdistal to the substrate.

In an embodiment, the disposing the drive transistor and the organiclight emitting diode on the substrate includes:

forming a color filter layer on a portion of the substrate and forming atransparent insulating layer on the color filter layer and a portion ofthe substrate so that the transparent insulating layer covers the colorfilter layer, and forming the first reflective electrode on thetransparent insulating layer so that only a part of the first reflectiveelectrode overlaps an edge portion of the color filter layer:

forming the light guide layer on an upper surface of the transparentinsulating layer at a position corresponding to the color filter layerso that a reflective structure is formed on a part of the light guidelayer except a bottom surface and a side surface proximal to the firstreflective electrode:

forming a planarization layer having an opening on an upper surface ofthe light guide layer, and an exposed upper surface of the transparentinsulating layer so that a portion of the first reflective electrode anda portion of the upper surface and the side surface of the light guidelayer proximal to the first reflective electrode are exposed, and sothat an edge of the first reflective electrode distal to the light guidelayer is spaced apart from the planarization layer to expose a portionof the upper surface of the transparent insulating layer proximal to theedge;

forming a transparent conductive layer on an upper surface of theplanarization layer, the exposed portion of the upper surface and theexposed side surface of the light guide layer, and the exposed portionof the upper surface of the first reflective electrode;

forming a light-reflecting material layer having an opening on an uppersurface of the transparent conductive layer, the remaining surface ofthe planarization layer, and the exposed portion of the upper surface ofthe transparent insulating layer, so as to expose a part of thetransparent conductive layer corresponding to the light incident surfaceof the light guide layer and the upper surface of the transparentconductive layer superposed with the first reflective electrode, therebyforming a first light-reflecting layer on the transparent conductivelayer covering the light guide layer and a second light-reflecting layerin contact with an edge of the transparent conductive layer distal tothe light guide layer and the exposed portion of the upper surface ofthe first reflective electrode;

forming a first insulating layer covering a formed structure;

forming an active layer and a second insulating layer separated fromeach other on a portion of the upper surface of the first insulatinglayer covering the first light-reflecting layer, and forming a gatedielectric layer on the active layer;

forming a gate on the gate dielectric layer and forming an electrodelayer on the second insulating layer;

forming an interlayer dielectric layer having a first via hole and asecond via hole to cover a formed structure so that the first via holeexposes only a portion of the active layer, and the second via holeexposes an edge of the active layer and a portion of the firstlight-reflecting layer:

forming a source, a drain, and a metal layer in the first via hole, inthe second via hole, and on the interlayer dielectric layer,respectively so that the metal layer is disposed opposite to theelectrode layer and electrically coupled to the drain;

forming a third insulating layer and a pixel defining layer successivelycovering the formed structure:

forming a third via hole penetrating the first insulating layer, theinterlayer dielectric layer, the third insulating layer and the pixeldefining layer to expose a portion of the transparent conductive layer:

forming the organic light emitting layer and the second reflectiveelectrode on the pixel defining layer and in the third via hole.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional diagram of a structure of an organic lightemitting display substrate disclosed in the related art,

FIG. 2a is a cross-sectional diagram of a structure of an organic lightemitting display substrate according to an embodiment of the presentdisclosure:

FIG. 2b is a planar diagram of a structure of an organic light emittingdisplay substrate according to an embodiment of the present disclosure;

FIGS. 3a to 3g are cross-sectional diagrams corresponding to structuresformed at respective steps of a method for manufacturing an organiclight emitting display substrate according to an embodiment of thepresent disclosure:

FIG. 4 is a flowchart of the method for manufacturing the organic lightemitting display substrate according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

To improve understanding of the technical solution of the presentdisclosure for those skilled in the art, the present disclosure will nowbe described in detail with the help of accompanying drawings andspecific embodiments.

In the present disclosure, two structures “disposed in the same layer”means that the two structures are formed by the same material layer, sothey are in the same layer in the layered relationship, which does notmean that they have the same distance relative to the substrate, or thatother layer structures between them and the substrate are identical.

In the present disclosure, a “patterning process” refers to a step offorming a structure having a specific pattern, which may be aphotolithography process including one or more of forming a materiallayer, coating photoresist, exposing, developing, etching, and peelingoff photoresist; obviously, the “patterning process” may also be anyother process such as an imprint process, an inkjet printing process,and the like.

An organic light emitting display substrate in the related art is shownin FIG. 1. The organic light emitting display is a bottom-emission typeorganic light emitting display substrate, including a thin filmtransistor 91 and an organic light emitting diode 92, where at least adielectric layer 94 and a planarization layer 15 are disposed betweenthe thin film transistor 91 and the organic light emitting diode 92, anda first electrode (such as an anode) of the organic light emitting diode92 is coupled to a drain of the thin film transistor 91 via a throughhole in the dielectric layer 94 and the planarization layer 15. Sincelight emitted by the organic light emitting diode can only exit througha transparent structure, a light outgoing surface cannot be formed at aposition of the thin film transistor 91, thus limiting a ratio of anarea of the light outgoing surface to the entire area of the organiclight emitting display substrate, resulting in a lower luminance of thelight emitting display device formed by the organic light emittingdisplay substrate.

In addition, the light emitted by the organic light emitting diode needsto pass through a plurality of same layers as for the thin filmtransistor 91, which increases light loss and results in a reducedluminance of the light emitting display device.

In an embodiment according to the present disclosure, as shown in FIGS.2a and 2b (FIG. 2b mainly reflects the relative positional relationshipbetween the light guide layer 14 and the organic light emitting diodefor emitting light; to better reflect positions of the above keystructures, some other structures are not shown in FIG. 2), an organiclight emitting display substrate including a substrate 10, and a drivetransistor and an organic light emitting diode disposed on the substrate10 is provided.

In a direction away from the substrate 10, the organic light emittingdiode successively includes: a first reflective electrode 13 (such as areflective anode), an organic light emitting layer 24, and a secondreflective electrode 25 (such as a reflective cathode). One side surfaceof the organic light emitting layer 24 is a light outgoing surface 241for emitting light, while the rest side surface is a non-light outgoingsurface. A drain 22 of the drive transistor is electrically coupled tothe first reflective electrode 13. For example, the organic lightemitting layer includes an upper surface facing the first reflectiveelectrode 13, a lower surface facing the second reflective electrode 25,and two side surfaces therebetween. One of the side surfaces is thelight outgoing surface, while the other is the non-light outgoingsurface. The upper surface, the lower surface and the non-light outgoingsurface herein may include a material capable of letting light to exit,but with a light-reflecting layer disposed outside the upper surface,the lower surface, and the non-light outgoing surface so that the lightis reflected back into the organic light emitting layer and emittedoutside only from the light outgoing surface.

The organic light emitting display substrate further includes a lightguide layer 14. One side surface of the light guide layer 14 is a lightincident surface 141, and the light incident surface 141 is disposedopposite to the light outgoing surface 241 of the organic light emittingdiode so that the light emitted from the light outgoing surface 241, forexample, enters the light guide layer 14 through a first insulatinglayer 30 as shown in FIG. 2. The light guide layer 14 is used forcausing the light entering from the light incident surface 141 to beemitted from a surface of the light guide layer 14 proximal to thesubstrate 10.

The first insulating layer 30 may be made of an inorganic insulatingmaterial such as SiOx, SiNx or AlOx, which is a transparent material anddoes not affect the light emitted from the light outgoing surface 241and entering the light guide layer 14.

The drive transistor is disposed at a side of the light guide layer 14distal to the substrate 10.

That is, the organic light emitting diode is disposed at a side of thelight guide layer 14, i.e., at a side proximal to the light incidentsurface 141 of the light guide layer 14; while the drive transistor isdisposed at a side of the light guide layer 14 distal to the substrate10. As a result, light emitted from one side surface (the light outgoingsurface 241) of the organic light emitting layer 24 can enter the lightguide layer 14 through the light incident surface 141, and be eventuallyuniformly emitted from a surface of the light guide layer 14 proximal tothe substrate 10 (a lower surface of the light guide layer 14).

In the organic light emitting display substrate of the presentembodiment, as shown in FIG. 2a , the light emitted from the entireorganic light emitting display substrate is finally emitted from thelower surface of the light guide layer 14 (thereby the organic lightemitting display substrate is in the form of a bottom-emission type,i.e., light is emitted outside through the substrate 10), while thedrive transistor is disposed at the side of the light guide layer 14distal to the substrate 10, so the position of the drive transistor willnot affect light emission. That is, the light guide layer 14 cantransmit light to a position corresponding to the drive transistor, andthe drive transistor does not limit a ratio of a light emitting area toan area of the entire organic light emitting display substrate. Thelight emitting area in the organic light emitting display substrate isdetermined by the lower surface of the light guide layer 14 so that theratio of the light emitting area to the area of the entire organic lightemitting display substrate is increased, thereby increasing theluminance of a light emitting display device including the organic lightemitting display substrate.

It can be seen that since the first reflective electrode 13 and thesecond reflective electrode 25 not only have electrical conductivity butalso are capable of reflecting light, light emitted from the organiclight emitting layer 24 can only be emitted outside from a side surface(the light outgoing surface 241) of the organic light emitting layer 24rather than the upper surface or the lower surface. Therefore, as shownin FIG. 2b , the organic light emitting diode actually emits light fromthe side surface of the organic light emitting layer 24, and thus may beequivalent to a line light source (i.e. a stripped portion at the rightside of FIG. 2b ). In this way, a volume of the organic light emittingdiode and thus a volume of the entire organic light emitting displaysubstrate are reduced. The light emitted from the line light sourceenters the light guide layer 14, and is then emitted outside from alower side of the light guide layer 14. That is, a light emitting areaof the organic light emitting display substrate (an actual area wherelight is emitted from the organic light emitting display substrate; thesliced portion at the left side of FIG. 2b ) is greater than an area ofthe organic light emitting diode that actually emits light. Thus, theactual luminance is not reduced with the line light source.

The light emitted from the organic light emitting layer 24 may generateresonance (i.e. form a microcavity, as shown by the dotted portion inFIG. 2b ) when being reflected between two electrodes of the organiclight emitting diode, thereby increasing an intensity of the light.However, in an existing organic light emitting diode, light is emittedfrom one of the electrodes, so the electrode should have a highertransmittance, which results in a reduced capability of light reflectionand a reduced resonance effect. In the organic light emitting displaysubstrate in the present disclosure, the organic light emitting layer 24emits light at a side surface, so that the first reflective electrode 13and the second reflective electrode 25 may have increased reflectioncapabilities, and light can be continuously reflected between the firstreflective electrode 13 and the second reflective electrode 25.Therefore, the organic light emitting diode herein is a light emittingdevice having a strong microcavity structure.

Meanwhile, since the light guide layer 14 is disposed on the uppersurface of the substrate 10 and may be in direct contact with thesubstrate 10, the light emitted from the lower surface of the lightguide layer 14 may not pass through a plurality of layers, therebyreducing light loss and thus increasing the brightness of the lightemitting display device.

In the embodiment as described above, a portion of the organic lightemitting layer 24 interposed between the first reflective electrode 13and the second reflective electrode 25 emits light, and the generatedlight will propagate upward, downward and sideward. In order to causethe generated light to be emitted outside only from the light outgoingsurface 241, a first reflective electrode 13 and a second reflectiveelectrode 25 having reflection capabilities are provided, and a secondlight-reflecting layer 18 is provided outside the side surface as thenon-light outgoing surface so that the light propagating in the threedirections is reflected back into the organic light emitting layer andcan only be emitted outside from the light outgoing surface 241.

FIG. 2a merely shows an example, but the present application is notlimited thereto, as long as the light generated from the organic lightemitting layer is restricted to be emitted outside only from one lightoutgoing surface, and the emitted light is introduced through the lightincident surface of the light guide layer. Therefore, in the presentapplication, the light outgoing surface may be one side surface of theorganic light emitting layer, or may be a portion of one side surface ofthe organic light emitting layer, or may include a portion of the upperor lower surface of the organic light emitting layer. In addition, inthe present application, the light incident surface of the light guidelayer may be a portion of the side surface of the light guide layer, ormay include a portion of the upper or lower surface the light guidelayer.

In an embodiment, the organic light emitting display substrate furtherincludes a first light-reflecting layer 17 disposed between the lightguide layer 14 and the drive transistor, and covering a surface of thelight guide layer 14 distal to the substrate 10.

That is, the first light-reflecting layer 17 separates the light guidelayer 14 from the drive transistor, and covers a surface of the entirelight guide layer 14 distal to the substrate 10 (the upper surface ofthe light guide layer 14).

The light entering the light guide layer 14 through the light incidentsurface 141 propagates in the light guide layer 14. When a part of thelight is emitted from the upper surface of the light guide layer 14, thefirst light-reflecting layer 17 on the upper surface of the light guidelayer 14 may reflect the light back into the light guide layer 14 sothat the light can be emitted outside from the lower surface of thelight guide layer 14, thus reducing light loss and increasing luminousbrightness.

In an embodiment, the organic light emitting display substrate furtherincludes: a transparent conductive layer 16 disposed between the firstlight-reflecting layer 17 and the light guide layer 14. At least a partof the transparent conductive layer 16 is superposed with the firstlight-reflecting layer 17, the transparent conductive layer 16 extendsbetween the light outgoing surface 241 and the light incident surface141 to be coupled to the first reflective electrode 13 of the organiclight emitting diode; and a drain 22 of the drive transistor is coupledto the first light-reflecting layer 17 made of a conductive material.

That is, the transparent conductive layer 16 is located on a lowersurface of the first light-reflecting layer 17, and superposed with thefirst light-reflecting layer 17, while the drive transistor is locatedon an upper surface of the first light-reflecting layer 17. Thetransparent conductive layer 16 extends between the light outgoingsurface 241 and the light incident surface 141 to be connected with thefirst reflective electrode 13. That is, the drain 22 of the drivetransistor is coupled to the first reflective electrode 13 of theorganic light emitting diode through the first light-reflecting layer 17and the transparent conductive layer 16.

Since the drive transistor is disposed above the light guide layer 14, aconnection structure between the drain 22 and the first reflectiveelectrode 13 will inevitably pass through a region between the lightincident surface 141 and the light outgoing surface 241. If theconnection structure is light-reflective, light cannot be incident intothe light guide layer 14 at the position of the connection structure. Asa result, the light utilization efficiency is reduced. Therefore, thetransparent conductive layer 16 may be used for extending through theregion between the light incident surface 141 and the light outgoingsurface 241 to conduct electricity.

In an embodiment, the transparent conductive layer 16 extends betweenthe organic light emitting layer 24 and the first reflective electrode13.

Specifically, the transparent conductive layer 16 is disposed betweenthe organic light emitting layer 24 and the first reflective electrode13. That is, a portion of the transparent conductive layer 16 is indirect contact with the organic light emitting layer 24. There are somerequirements for properties of the electrodes in an organic lightemitting diode in contact with the organic light emitting layer 24,where the anode is generally made of a transparent conductive materialsuch as indium tin oxide (ITO), while the reflective electrode isgenerally made of a metal or the like. Direct contact between the firstreflective electrode 13 and the organic light emitting layer 24 mayaffect the performance of the organic light emitting diode. Therefore,the transparent conductive layer 16 may be disposed between the organiclight emitting layer 24 and the first reflective electrode 13 so thatthe requirements for properties of the first electrode (anode) aresatisfied.

Optionally, the organic light emitting display substrate of theembodiment further includes: an electrode layer 20 disposed in the samelayer as a gate of the drive transistor, and coupled to the gate. Theelectrode layer 20 corresponds to (i.e., is disposed opposite to) atleast a part of the first light-reflecting layer 17 to form a firstcapacitor.

Specifically, the electrode layer 20 and the first light-reflectinglayer 17 form a first capacitor which may be a storage capacitor.

The electrode layer 20 coupled to the gate may avoid floating of theelectrode layer 20, and ensure effectiveness of the storage capacitorformed by the electrode layer 20 and the first light-reflecting layer17.

Optionally, the organic light emitting display substrate of theembodiment further includes: a metal layer 26 disposed in the same layeras the drain 22 of the drive transistor at a side of the electrode layer20 distal to the substrate 10, and coupled to the drain 22. At least apart of the metal layer 26 corresponds to the electrode layer 20 to forma second capacitor.

Here, the second capacitor is composed of the electrode layer 20 and theopposite metal layer 26. Therefore, the resultant storage capacitor is astack of capacitors formed by the electrode layer 20 with the oppositemetal layer 26 and with the first light-reflecting layer 17.

The stack of capacitors not only reduces an area occupied by the storagecapacitor, but also increases the capacity of the storage capacitor,thereby improving the performance of the organic light emitting displaysubstrate.

Optionally, the organic light emitting display substrate of theembodiment further includes: a second light-reflecting layer 18 disposedoutside the non-light outgoing surface of the organic light emittinglayer, and configured to reflect light emitted from the non-lightoutgoing surface back into the organic light emitting layer.

In that, for example, when the organic light emitting layer 24 is apolygonal layered structure (such as a square layered structure or arectangular layered structure), since the light outgoing surface 241 maybe only one of the side surfaces, the light emitted by the organic lightemitting layer 24 may be emitted outside from other non-light outgoingsurfaces. In this case, the second light-reflecting layer 18 is disposedoutside the non-light outgoing surface, and reflects light back into theorganic light emitting layer 24 so that the light is only emitted fromthe light outgoing surface 241 of the organic light emitting layer 24,thus further reducing light loss and increasing the luminous brightness.Specifically, the second light-reflecting layer 18 may be disposed inthe same layer as the first light-reflecting layer 17. Obviously, firstreflective electrodes 13 in different sub-pixels should be disconnectedfrom each other. Therefore, as shown in FIG. 2b , when coupled to thefirst reflective electrode 13, the second light-reflecting layer 18cannot be coupled to a light-reflecting layer of any other sub-pixel.

Optionally, the light guide layer 14 includes: a reflective structuredisposed on each surface of the light guide layer 14 except the lightincident surface 141 and the surface proximal to the substrate 10, andconfigured to reflect light emitted from inside of the light guide layer14 back into the light guide layer 14.

That is, except the light incident surface 141 and the lower surface ofthe light guide layer 14, each of the remaining surfaces of the lightguide layer 14 is provided with a reflective structure. Optionally, thereflective structure on a top surface of the light guide layer 14 may bea convex structure, such as a sphere or a cube, while the reflectivestructure on a side surface of the light guide layer 14 may be asawtooth structure.

The reflective structure of the light guide layer 14 may reflect thelight entering the light guide layer 14 as much as possible, and reducelight emission from other surfaces than the lower surface of the lightguide layer 14, thereby reducing light loss.

Optionally, at least a part of the second reflective electrode 25 isdisposed at a side of the drive transistor distal to the substrate 10and covers the drive transistor.

That is, the second reflective electrode 25 may cover the entire drivetransistor and the organic light emitting diode.

In this way, complete light shielding for the drive transistor can beachieved by the second reflective electrode 25 and the firstlight-reflecting layer 17, thus effectively improving the reliability ofthe organic light emitting display substrate.

Optionally, the organic light emitting display substrate of theembodiment further includes: a planarization layer 15 disposed at a sideof the light guide layer 14 distal to the substrate 10 and in contactwith the light guide layer 14. The planarization layer 15 has arefractive index smaller than that of the light guide layer 14.

That is, the planarization layer 15 may be located between the lightguide layer 14 and the transparent conductive layer 16.

The planarization layer 15 having a refractive index smaller than thatof the light guide layer 14 can ensure that the light in the light guidelayer 14 is totally reflected as much as possible by an interfacebetween the light guide layer 14 and the planarization layer 15, thusreducing light loss.

Optionally, the organic light emitting display substrate of theembodiment further includes: a color filter layer 11 disposed at a sideof the light guide layer 14 proximal to the substrate 10; and atransparent insulating layer 12 disposed between the color filter layer11 and the light guide layer 14. The transparent insulating layer 12 hasa refractive index greater than that of the light guide layer 14.

The color filter layer 11 has a color corresponding to actualconditions, such as red, yellow, and the like. The transparentinsulating layer 12 having a refractive index greater than that of thelight guide layer 14 aims to prevent the light in the light guide layer14 from being totally reflected at an interface between the light guidelayer 14 and the transparent insulating layer 12.

According to an embodiment of the present application, as shown in FIGS.2a, 2b, and 3a to 3g , the embodiment provides a method formanufacturing an organic light emitting display substrate as shown inFIG. 4, including the following steps S10 to S80:

At the step S10, as shown in FIG. 3a , a color filter layer 11, atransparent insulating layer 12, and a first reflective electrode 13 isformed on a substrate 10 by a patterning process.

Specifically, at a step S11, the color filter layer 11 is formed on anupper surface of the substrate 10. The color filter layer 11 may have acolor corresponding to actual conditions, such as red, yellow, and thelike.

At step S12, the transparent insulating layer 12 is formed on the colorfilter layer 11 and a portion of the upper surface of the substrate 10,and the transparent insulating layer 12 covers the color filter layer11.

At step S13, the first reflective electrode 13 (such as a reflectiveanode) is formed on an upper surface of the transparent insulating layer12, where most of the first reflective electrode 13 does not cover thecolor filter layer 11, and only a portion proximal to an edge of thefirst reflective electrode 13 overlaps the color filter Layer 11.

At the step S20, as shown in FIG. 3b , a light guide layer 14 is formed.

Specifically, a light guiding material is coated on a part of the uppersurface of the transparent insulating layer 12 corresponding to thecolor filter layer 11 to form the light guide layer 14. The lightguiding material includes, but is not limited to, one or more of acryldiethylene glycol carbonate, polymethyl methacrylate, polycarbonate,polystyrene.

A reflective structure is formed on each surface of the light guidelayer 14 except a bottom surface and a side surface (i.e., the lightincident surface 141) corresponding to the first reflective electrode13. The reflective structure on a top surface of the light guide layer14 may be a convex structure, such as a sphere or a cube, while thereflective structure on a side surface of the light guide layer 14opposite to the light incident surface 141 may be a sawtooth structure.

At the step S30, as shown in FIG. 3c , a planarization layer 15, atransparent conductive layer 16, a first light-reflecting layer 17, anda second light-reflecting layer 18 are formed.

Specifically, at a step S31, a planarization film is formed on an uppersurface of the light guide layer 14, an upper surface of the firstreflective electrode 13, and an exposed upper surface of the transparentinsulating layer 12. An opening is formed in the planarization filmbased on a preset pattern so that a portion of the first reflectiveelectrode 13 and a portion of the upper surface and the side surface ofthe light guide layer 14 proximal to the first reflective electrode 13are exposed, and an edge of the first reflective electrode 13 distal tothe light guide layer 14 is spaced apart from the transparent insulatinglayer 12 to expose the upper surface of the transparent insulating layer12 proximal to the edge, thus forming the planarization layer 15. Amaterial of the planarization layer 15 includes, but is not limited to,a material having a planarization effect such as a polysiloxane-basedmaterial, an acrylic-based material, or a polyimide-based material.

At a step S32, a transparent conductive layer 16 is formed on an uppersurface of the planarization layer 15, the exposed portion of uppersurface and side surface of the light guide layer 14, and the exposedupper surface of the first reflective electrode 13.

At a step S33, a light-reflecting material layer is formed on the uppersurface of the transparent conductive layer 16, the remaining uppersurface of the planarization layer 15 and the exposed transparentinsulating layer 12. An opening is formed in the light-reflectingmaterial layer based on a preset pattern by a patterning process so asto expose the transparent conductive layer 16 corresponding to the lightincident surface 141 of the light guide layer 14 and the upper surfaceof the transparent conductive layer 16 superposed with the firstreflective electrode 13, thus forming the first light-reflecting layer17 and the second light-reflecting layer 18. That is, the openingdivides the light-reflecting material layer into two parts, where one isthe first light-reflecting layer 17 covering the light guide layer 14,and the other is the second light-reflecting layer 18 in contact with anedge of the transparent conductive layer 16 distal to the light guidelayer 14 and an edge of the first reflective electrode 13 distal to thelight guide layer 14.

At the step S40, as shown in FIG. 3d , an active layer of the drivetransistor, a gate of the drive transistor and an electrode layer 20 areformed.

Specifically, at a step S41, a first insulating layer 30 is formed,where the first insulating layer completely covers an upper surface ofthe formed layer structure.

At a step S42, the active layer and a second insulating layer are formedon an upper surface of the first insulating layer covering the firstlight-reflecting layer 17, where the active layer is not coupled to thesecond insulating layer. A gate dielectric layer is formed at a positionnear a center of the active layer.

At a step S43, the gate on the gate dielectric layer and the electrodelayer 20 on the second insulating layer are formed simultaneity by apatterning process.

At a step S44, an interlayer dielectric layer 19 is formed on each ofthe exposed layer structures, where the interlayer dielectric layer 19completely covers the formed structure. A first via hole is formed inthe interlayer dielectric layer 19 based on a preset pattern, where thefirst via hole is only coupled to the active layer to expose only aportion of an upper surface of the active layer. A second via hole isformed in the interlayer dielectric layer 19 and the first insulatinglayer based on a preset pattern, where the second via hole is located atan edge of the active layer and exposes the edge of the active layer anda portion of the upper surface of the first insulating layer, as well asa portion of the upper surface of the first light-reflecting layer.

At the step S50, as shown in FIG. 3e , a source 21, a drain 22 and ametal layer 26 are formed.

Specifically, a metal material layer is formed on the interlayerdielectric layer 19, in the first via hole, and in the second via hole,and a part of the metal material layer other than those parts intendedfor the source 21, the drain 22, and the metal layer 26 is removed basedon a preset pattern to form the source 21, the drain 22, and the metallayer 26. The source 21 is located at the first via hole, the drain 22is located at the second via hole, and the metal layer 26 is disposedopposite to the electrode layer 20 and electrically coupled to the drain22.

At the step S60, as shown in FIG. 3f , a third insulating layer 27 and apixel defining layer 23 are formed.

Specifically, at a step S61, the third insulating layer 27 is formed onthe interlayer dielectric layer 19, the source 21, the drain 22, and themetal layer 26 so that the third insulating layer 27 covers all theformed layer structures.

At a step S62, a pixel defining layer 23 is formed on the thirdinsulating layer 27. Optionally, an upper surface of the pixel defininglayer 23 is planar. The pixel defining layer 23 is used for separatinglight emitting regions in adjacent sub-pixels of the organic lightemitting display substrate.

At the step S70, as shown in FIG. 3g , a third via hole is formed.

Specifically, a third via hole is formed in the pixel defining layer 23,the third insulating layer 27, the interlayer dielectric layer 19, andthe first insulating layer corresponding to the first reflectiveelectrode 13 based on a preset pattern, thereby exposing a portion ofthe transparent conductive layer 16 that corresponds to a portion of thefirst reflective electrode 13.

At the step S80, as shown in FIGS. 2a and 2b , an organic light emittinglayer 24 and a second reflective electrode 25 are formed.

Specifically, at a step S81, the organic light emitting layer 24 isformed on the pixel defining layer 23 and in the third via hole so thatthe organic light emitting layer 24 covers all the formed structures.

At a step S82, a second reflective electrode 25 (such as a reflectivecathode) is formed on the organic light emitting layer 24 to form anorganic light emitting diode, where at least a part of the secondreflective electrode 25 covers the drive transistor.

In addition, the gate, the source 21, the drain 22, and the electrodelayer 20 in the present disclosure may be made of a commonly used metalmaterial such as Ag, Cu. Al, Mo, etc., or may be multilayer metals suchas MoNb/Cu/MoNb, or the like, or may be made of an alloy material of theabove metals, such as AlNd, MoNb, etc., or may be a stacked structuremade of a metal and a transparent conductive oxide (such as ITO, AZO,etc.), such as ITO/Ag/ITO, or the like. The material of the interlayerdielectric layer 19, the first insulating layer, the second insulatinglayer and the third insulating layer 27 in the present disclosureincludes, but are not limited to, a conventional dielectric materialsuch as SiOx, SiNx, SiON, or any new type of organic insulating materialor a high dielectric constant (High k) material such as AlOx, HfOx,TaOx, etc.

The transparent conductive layer 16 in the present disclosure may bemade of a transparent conductive oxide such as ITO, AZO, or the like.

The first light-reflecting layer 17, the second light-reflecting layer18, the first reflective electrode 13, and the second reflectiveelectrode 25 in the present disclosure are made of a material that isboth electrically conductive and light-reflective, such as a metalmaterial.

It should be understood that the above embodiments are merely exemplaryembodiments for the purpose of illustrating the principle of thedisclosure, and the disclosure is not limited thereto. Variousmodifications and improvements can be made by a person having ordinaryskill in the art without departing from the spirit and essence of thedisclosure. Accordingly, all of the modifications and improvements alsofall into the protection scope of the disclosure.

What is claimed is:
 1. An organic light emitting display substrate,comprising a substrate, and a drive transistor and an organic lightemitting diode disposed on the substrate, wherein in a direction awayfrom the substrate, the organic light emitting diode successivelycomprises a first reflective electrode, an organic light emitting layer,and a second reflective electrode, the organic light emitting layercomprises a light outgoing surface through which light is emittedoutside from the organic light emitting layer and a non-light outgoingsurface through which no light is emitted outside from the organic lightemitting layer, and a drain of the drive transistor is electricallycoupled to the first reflective electrode; the organic light emittingdisplay substrate further comprises: a light guide layer comprising alight incident surface through which light is incident into the lightguide layer, where the light incident surface is disposed opposite tothe light outgoing surface of the organic light emitting diode so thatthe light emitted from the light outgoing surface enters the light guidelayer which is configured to cause the light entering from the lightincident surface to be emitted from a surface of the light guide layerproximal to the substrate; and the drive transistor is disposed at aside of the light guide layer distal to the substrate.
 2. The organiclight emitting display substrate according to claim 1, wherein one sidesurface of the organic light emitting layer is the light outgoingsurface, while the rest side surface is the non-light outgoing surface;and one side surface of the light guide layer is the light incidentsurface.
 3. The organic light emitting display substrate according toclaim 2, further comprising a first insulating layer disposed betweenthe light outgoing surface and the light incident surface, wherein thelight incident surface and the light outgoing surface are disposedopposite to each other by the first insulating layer.
 4. The organiclight emitting display substrate according to claim 3, wherein the firstinsulating layer is made of a transparent material.
 5. The organic lightemitting display substrate according to claim 4, wherein the transparentmaterial comprises an inorganic insulating material selected from agroup consisting of SiOx, SiNx, and AlOx.
 6. The organic light emittingdisplay substrate according to claim 1, further comprising: a firstlight-reflecting layer disposed between the light guide layer and thedrive transistor, and covering a surface of the light guide layer distalto the substrate.
 7. The organic light emitting display substrateaccording to claim 6, further comprising a transparent conductive layerdisposed between the first light-reflecting layer and the light guidelayer, wherein at least a part of the transparent conductive layer issuperposed with the first light-reflecting layer, and the transparentconductive layer extends between the light outgoing surface and thelight incident surface to be coupled to the first reflective electrodeof the organic light emitting diode; and a drain of the drive transistoris coupled to the first light-reflecting layer made of a conductivematerial.
 8. The organic light emitting display substrate according toclaim 7, wherein the transparent conductive layer extends between theorganic light emitting layer and the first reflective electrode.
 9. Theorganic light emitting display substrate according to claim 7, furthercomprising an electrode layer disposed in a same layer as a gate of thedrive transistor, and coupled to the gate; wherein the electrode layeris disposed opposite to at least a part of the first light-reflectinglayer to form a first capacitor.
 10. The organic light emitting displaysubstrate according to claim 9, further comprising a metal layerdisposed in a same layer as the drain of the drive transistor at a sideof the electrode layer distal to the substrate, and coupled to thedrain; wherein at least a part of the metal layer is disposed oppositeto the electrode layer to form a second capacitor.
 11. The organic lightemitting display substrate according to claim 1, further comprising: asecond light-reflecting layer disposed outside the non-light outgoingsurface of the organic light emitting layer, and configured to reflectlight emitted from the non-light outgoing surface back into the organiclight emitting layer.
 12. The organic light emitting display substrateaccording to claim 1, wherein the light guide layer comprises: areflective structure disposed on each surface of the light guide layerexcept the light incident surface and the surface proximal to thesubstrate, and configured to reflect light emitted from inside of thelight guide layer toward the surface back into the light guide layer.13. The organic light emitting display substrate according to claim 1,wherein at least a part of the second reflective electrode is disposedat a side of the drive transistor distal to the substrate and covers thedrive transistor.
 14. The organic light emitting display substrateaccording to claim 1, further comprising: a planarization layer disposedat the side of the light guide layer distal to the substrate, and incontact with the light guide layer, the planarization layer having arefractive index smaller than that of the light guide layer.
 15. Theorganic light emitting display substrate according to claim 1, furthercomprising: a color filter layer disposed at a side of the light guidelayer proximal to the substrate; and a transparent insulating layerdisposed between the color filter layer and the light guide layer, thetransparent insulating layer having a refractive index greater than thatof the light guide layer.
 16. A method for manufacturing an organiclight emitting display substrate, comprising: disposing a drivetransistor and an organic light emitting diode on a substrate so that ina direction away from the substrate, the organic light emitting diodesuccessively comprises a first reflective electrode, an organic lightemitting layer, and a second reflective electrode, the organic lightemitting layer comprises a light outgoing surface through which light isemitted outside from the organic light emitting layer and a non-lightoutgoing surface through which no light is emitted outside from theorganic light emitting layer, and a drain of the drive transistor iselectrically coupled to the first reflective electrode; wherein thedisposing the drive transistor and the organic light emitting diode onthe substrate further comprises disposing a light guide layer on thesubstrate so that the light guide layer comprises a light incidentsurface through which light is incident into the light guide layer, thelight incident surface is disposed opposite to the light outgoingsurface of the organic light emitting diode, the light emitted from thelight outgoing surface enters the light guide layer which is configuredto cause the light entering from the light incident surface to beemitted from a surface of the light guide layer proximal to thesubstrate, and the drive transistor is disposed at a side of the lightguide layer distal to the substrate.
 17. The method according to claim16, wherein one side surface of the organic light emitting layer is thelight outgoing surface, while the rest side surface is a non-lightoutgoing surface; and one side surface of the light guide layer is thelight incident surface.
 18. The method according to claim 17, whereinthe disposing the drive transistor and the organic light emitting diodeon the substrate comprises: forming a color filter layer on a portion ofthe substrate and forming a transparent insulating layer on the colorfilter layer and a portion of the substrate so that the transparentinsulating layer covers the color filter layer, and forming the firstreflective electrode on the transparent insulating layer so that only aportion of the first reflective electrode overlaps an edge portion ofthe color filter layer; forming the light guide layer on an uppersurface of the transparent insulating layer at a position correspondingto the color filter layer so that a reflective structure is formed on apart of the light guide layer except a bottom surface and a side surfaceproximal to the first reflective electrode; forming a planarizationlayer having an opening on an upper surface of the light guide layer,and an exposed upper surface of the transparent insulating layer so thata portion of the first reflective electrode and a portion of the uppersurface and the side surface of the light guide layer proximal to thefirst reflective electrode are exposed, and so that an edge of the firstreflective electrode distal to the light guide layer is spaced apartfrom the planarization layer to expose a portion of the upper surface ofthe transparent insulating layer proximal to the edge; forming atransparent conductive layer on an upper surface of the planarizationlayer, the exposed portion of the upper surface and the exposed sidesurface of the light guide layer, and the exposed portion of the uppersurface of the first reflective electrode; forming a light-reflectingmaterial layer having an opening on an upper surface of the transparentconductive layer, the remaining surface of the planarization layer, andthe exposed portion of the upper surface of the transparent insulatinglayer, so as to expose a part of the transparent conductive layercorresponding to the light incident surface of the light guide layer andthe upper surface of the transparent conductive layer superposed withthe first reflective electrode, thereby forming a first light-reflectinglayer on the transparent conductive layer covering the light guide layerand a second light-reflecting layer in contact with an edge of thetransparent conductive layer distal to the light guide layer and theexposed portion of the upper surface of the first reflective electrode;forming a first insulating layer covering a formed structure; forming anactive layer and a second insulating layer separated from each other ona portion of the upper surface of the first insulating layer coveringthe first light-reflecting layer, and forming a gate dielectric layer onthe active layer; forming a gate on the gate dielectric layer andforming an electrode layer on the second insulating layer; forming aninterlayer dielectric layer having a first via hole and a second viahole to cover a formed structure so that the first via hole exposes onlya portion of the active layer, and the second via hole exposes an edgeof the active layer and a portion of the first light-reflecting layer;forming a source, a drain, and a metal layer in the first via hole, inthe second via hole, and on the interlayer dielectric layer,respectively so that the metal layer is disposed opposite to theelectrode layer and electrically coupled to the drain; forming a thirdinsulating layer and a pixel defining layer successively covering aformed structure; forming a third via hole penetrating the firstinsulating layer, the interlayer dielectric layer, the third insulatinglayer and the pixel defining layer to expose a portion of thetransparent conductive layer; and forming the organic light emittinglayer and the second reflective electrode on the pixel defining layerand in the third via hole.
 19. The organic light emitting displaysubstrate according to claim 18, wherein the first insulating layer ismade of a transparent material.
 20. The organic light emitting displaysubstrate according to claim 19, wherein the transparent materialcomprises an inorganic insulating material selected from a groupconsisting of SiOx, SiNx, and AlOx.